U.S. patent number 8,313,208 [Application Number 12/892,063] was granted by the patent office on 2012-11-20 for in-grade lighting system.
This patent grant is currently assigned to ABL IP Holding LLC. Invention is credited to Michael P. Leonhardt, Richard M. Schuler, Glenn M. Tyson.
United States Patent |
8,313,208 |
Tyson , et al. |
November 20, 2012 |
In-grade lighting system
Abstract
A lighting system has a sealable housing with a lamp cavity, a
junction box and a partition wall there between with the junction
box being laterally from beneath a lens opening. The system further
includes a closure to close an access port in the partition wall
which includes a conical wall with a circular plate truncating the
wall. The plate extends across the bottom of the housing and a
vertically extending sealing flange receives the closure. A ballast
assembly is also located from beneath the lens opening. A formed
seal is positioned about a lens which extends inwardly to capture
optic components beneath the lens. A locking ring is restrained
from compressing against the mounting flange of the lens. A
lighting system employing an LED board array and LED power control
includes a heat sink beneath the board array extending downwardly
to a radiator for transfer of heat from the array downwardly to the
lamp cavity for dissipation.
Inventors: |
Tyson; Glenn M. (La Crescenta,
CA), Schuler; Richard M. (Long Beach, CA), Leonhardt;
Michael P. (Castaic, CA) |
Assignee: |
ABL IP Holding LLC (Conyers,
GA)
|
Family
ID: |
40679009 |
Appl.
No.: |
12/892,063 |
Filed: |
September 28, 2010 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20110032709 A1 |
Feb 10, 2011 |
|
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
11945414 |
Oct 5, 2010 |
7806550 |
|
|
|
Current U.S.
Class: |
362/153.1;
362/373; 362/153 |
Current CPC
Class: |
F21V
31/005 (20130101); E01F 9/559 (20160201); F21V
15/01 (20130101); F21V 23/026 (20130101); F21V
21/30 (20130101); F21S 8/022 (20130101); F21Y
2115/10 (20160801) |
Current International
Class: |
E01F
9/00 (20060101) |
Field of
Search: |
;362/153,153.1,364-366,373-375,158,645,267,455,418,427,429,436 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Carter; William
Attorney, Agent or Firm: Connolly Bove Lodge & Hutz
LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No.
11/945,414, filed Nov. 27, 2007, now U.S. Pat. No. 7,806,550,
issued Oct. 5, 2010, the disclosure of which is incorporated herein
by reference.
Claims
What is claimed is:
1. A lighting system comprising a sealable housing including a
bottom wall, a top wall having a first portion with a lens seat
extending upwardly from the top wall to define a lens opening and a
closed second portion extending laterally from the lens seat, a
cavity between the top wall and the bottom wall extending beneath
the first and second portions of the top wall; a light emitting
diode power control in the cavity, the second portion of the top
wall extending fully above the light emitting diode power control;
a light emitting diode array directly beneath the lens opening; a
radiator in the cavity directly beneath the array and in thermal
contact with the light emitting diode array, the radiator being
constructed and arranged to radiate through the cavity to directly
beneath the second portion of the top wall.
2. The lighting system of claim 1, wherein the sealable housing
further includes a junction box between the cavity and the bottom
wall and having a port accessible into the junction box directly
below the lens opening
3. The lighting system of claim 1 further comprising a heat sink
directly beneath the array constructed and arranged to provide
thermal contact between the array above and the radiator below and
including a plate and a thermal block depending from the plate in
thermal contact with the plate, the radiator is around and in
thermal contact with the thermal block and the radiator includes
fins, the heat sink, radiator and light emitting diode array are in
the cavity.
4. The lighting system of claim 3, wherein the heat sink and the
radiator are separately formed.
Description
BACKGROUND OF THE INVENTION
The field of the present invention is in-grade lighting
systems.
In-grade lighting systems have an infinite number of applications
for both indoor and outdoor illumination. Among long-term design
issues of concern here, lamp profile for flexible application,
maintenance with continued integrity and cooling are addressed.
For indoor applications, in-grade lighting is often utilized to
provide general illumination or accent illumination to interior
walls and objects in public spaces where the use of surface mounted
or exposed fixtures are subjected to vandalism, or where the
placement of available electrical service requires its use.
In outdoor applications, such lighting systems can be used to
illuminate and thus enhance the effects of a variety of objects
such as flag poles, signs, shrubbery, and other architectural
points of interest. Outdoor lighting can also provide general flood
lighting to areas for security purposes and spotlighting where
desired.
In-grade lighting systems are also used in semi-indoor areas such
as parking structures to separate vehicular traffic flow from
pedestrian traffic, or in transitional spaces such as the parapets
of buildings to illuminate architectural elements which require the
lighting sources to be hidden completely from view.
As lighting systems in outdoor applications are subject to a wide
variety of conditions, particular attention must be directed to
long-term survival. Thermal cycling, moisture, corrosive soils,
vehicle and foot traffic, periodic maintenance and the like are
particularly problematic for in-grade lighting applications.
Further, in-grade lighting is found in hardscape applications which
make removal and replacement of in-grade fixtures highly
undesirable.
For indoor lighting system applications, the depth of the fixture
creates challenges in placing them in areas with limited space
between floor and ceiling structures. Generally, eight inches has
been determined to be the maximum depth acceptable in such
multi-story structures, limiting the variety of lamp types
available. The general practice of installing electrical supply
wiring after fixture housing installation requires direct access to
the junction box. With limited depth requirements, junction boxes
traditionally have been small and difficult to seal. Electrical
supply wiring is solid wire, making its manipulation into a small
junction box after fixture splicing difficult. Routing of the
spliced wires out of the junction box to the lamp and ballast
assemblies within the fixture is further complicated with the
limited space.
In-grade lighting can have the problem of accumulating dirt and
debris about the lens. Opening the lighting system for maintenance,
such as relamping, can allow that material to become lodged further
into the fixture. This can interfere with clearance, fit and
sealing. Such changes can later result in spontaneous failure or
failure under repeated vehicle or pedestrian loading on the lens.
Such problems can be further aggravated by the size of the opening
required to accommodate a given size lens sight glass. The greater
the overall diameter of the lamp at grade, the greater the exposure
and force interactions with the fixture.
The foregoing applications and environmental challenges have long
been recognized with various design efforts undertaken to
satisfactorily meet such challenges. U.S. Reissue Pat. No. 34,709,
and U.S. Pat. Nos. 5,198,962; 5,276,583; 5,408,397; 5,486,988;
5,727,873; 6,068,384; all incorporated herein by reference,
describe lighting systems and construction that address the
challenges of in-grade lighting design. The construction includes
improved sealing mechanisms for lighting assemblies, non corroding
materials and rugged structures providing improved and reliable
indoor and outdoor lighting features.
The heat generated by in-grade lighting systems are of particular
concern in the design of indoor applications due to the increased
risk of direct contact by the persons occupying the space. This
again limits the lamp type availability. These design challenges,
particularly in the setting of a sealable lamp housing, are
interrelated with changes made to accommodate one challenge often
adversely impacting other challenges. Reducing lamp profile
adversely impacts variety of lamp offerings, access for relamping
and increases heat load. Maintenance, particularly as affecting
continued sealing integrity, is adversely impacted by reduction in
lamp housing space such as would accompanying reduction in the lamp
profile. Cooling needs traditionally are contrary to small housings
and are adversely impacted by sealing of the housing which impacts
convection. Reduced lamp profile also can adversely impact long
demanded features such as the ability to aim the light
independently of the housing. Further, where profile is an issue in
in-grade applications, flow through cooling which necessarily
allows water entry as well, is often inappropriate.
Of long-term concern to those engaged in the design of in-grade
lighting fixtures is the provision of lamps for applications
in-grade where a highly permanent installation requires long-term
reliability, e.g., an in-grade application embedded in a concrete
drive or flooring. The longevity of architectural features are
typically measured in decades. During that time, even the most
reliable fixture will require maintenance to replace the light
source. Such maintenance can require lamp replacements, ballast
assembly replacements and entry to the junction box and is beyond
the control of the designer. As such, accommodating maintenance
activity requires virtually foolproof means of reassembly to
maintain the sealed integrity of the overall system and the
components thereof.
Versatility of application with longevity and repeatable
maintenance has long remained a design challenge. Typically
components are stacked vertically in in-grade fixtures. This
provides easy access through the lens opening for maintenance.
Reference is made to the foregoing teachings incorporated herein by
reference. With this convention, however, versatility of
application is compromised where a relatively deep installation is
inappropriate. This is particularly true of the junction box where
the wiring is relatively fixed. Components such as lamps, emitters,
ballasts and electronic controls can be accessed and even pulled
from the housing through the lens opening, given modular
construction and ample leads. Rewiring, however, typically requires
reentry into the junction box.
SUMMARY OF THE INVENTION
The present invention is directed to sealed in-grade fixture design
providing versatile lamp profiles with adequate provision for
maintenance and other features. In a separate invention,
counterintuitive thermal flow is created to enhance longevity of
light generating components. The lighting system includes a
sealable housing with a top wall, a bottom wall, a lens seat in the
top wall defining a lens opening, a cavity, a junction box between
the top and bottom walls and a partition wall bifurcating the
housing between the cavity and the junction box.
In a first separate aspect of the present invention, an LED power
control is presented within the lamp cavity. An LED board array is
positioned directly beneath the lens opening. A radiator is in the
lamp cavity directly below the LED board array. The radiator is
constructed and arranged to radiate to directly beneath the second
closed portion of the top wall. The radiated heat could then pass
through the substantially greater housing surfaces, the extent of
which being dictated by the presence of the LED power control,
laterally of the lens opening.
In a second separate aspect of the present invention, an LED power
control is presented within the lamp cavity. An LED board array is
positioned directly beneath the lens opening. A heat sink is
arranged beneath the board array which includes a plate coextensive
and in thermal contact with the board array. The heat sink further
includes a thermal block depending from the plate and in thermal
conductivity with a radiator having radially extending fins. This
radiator is in the lamp cavity directly below the LED board array.
The radiator is constructed and arranged to radiate to directly
beneath the second closed portion of the top wall. In a closed
housing, heat tends to stratify through convection adjacent the
lens in an in-grade fixture. Through the heat sink and the
radiator, heat is conducted down and then radiated outwardly in a
nonintuitive inversion. The radiated heat could then pass through
the substantially greater housing surfaces, the extent of which
being dictated by the presence of the LED power control, laterally
of and below the lens opening.
In a third separate aspect of the present invention, any of the
foregoing separate aspects are contemplated to be employed in
combination to greater advantage.
Accordingly, it is a principal object of the present invention to
provide an improved sealed in-grade LED light fixture. Other and
further objects and advantages will appear hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an assembled in-grade fixture.
FIG. 2 is a cross-sectional side view of the in-grade fixture taken
through a centerline of the housing.
FIG. 3 is a cross-sectional end view of the in-grade fixture
looking toward the junction box from the centerline of the fastener
and the closure.
FIG. 4 is a perspective view of a socket assembly for a
conventional reflectorized lamp.
FIG. 5 is a perspective view of a light source having a separate
reflector defining a socket assembly.
FIG. 6 is an exploded perspective view of a closure.
FIG. 7 is a cross-sectional detail of the lens and lens seat.
FIG. 8 is a cross-sectional side view taken through the centerline
of the housing with an LED board array.
FIG. 9 is a perspective view of an assembled LED board array with
radiator.
FIG. 10 is an exploded perspective view of the assembly for an LED
board array and radiator.
FIG. 11 is an exploded perspective view of a lens, gasket and
locking ring.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIGS. 1 through 7, a conventional light source is
associated with a low profile fixture. A housing, generally
designated 20, is principally fabricated from three body parts
which are molded and define a top body portion 22, a closure plate
52, and a bottom body portion 24. These portions 22, 24, and 52
meet at tongue and groove joints which are bonded to fully seal the
joint and retain the housing 20 together as an integral unit. As
the joint is about the waist of the housing 20, the top and bottom
body portions 22, 24 join together to form peripheral sides of the
housing 20.
The top body portion 22 extends to form a top wall 26. This top
body portion 22 further defines a lens seat, generally designated
28, which extends upwardly and defines a lens opening 30. An outer
cylindrical body 32 creates the lens seat 28 in its extension
upwardly from the top wall 26. The outer cylindrical body 32
includes an annular mounting shelf 34 that is inwardly of an upper
edge 36. A cylindrical sealing flange 38 extends upwardly as well.
A cylindrical passageway 40 extends downwardly from the cylindrical
sealing flange 38 to an annular retaining flange 42. The annular
mounting shelf 34 further includes three holes 44 equiangularly
spaced about the outer cylindrical body 32 with threaded inserts 46
therein to receive fasteners for retaining a lens.
The bottom body portion 24 and the closure plate 52 assembled
therewith define a bottom wall 48. An access hole 50, principally
below a junction box that is defined within the housing 20, is
closed by the closure plate 52. A plurality of fasteners 54
physically retain the closure plate 52 in a sealed relationship
with the access hole 50 in further defining the bottom wall 48. The
closure plate 52 is preferably bonded to the bottom wall 48. The
fasteners 54 extend into predrilled holes 56 from the closure plate
52 into the bottom body portion 24. A tongue and groove peripheral
joint between the closure plate 52 and the bottom body portion 24
enhances sealing and placement. The access hole 50 is convenient
for molding the bottom body portion 24 and for placement of a
grommet, described below, before bonding in place.
Between the bottom wall 48 and the top wall 26 and integrally
formed as part of the bottom body portion 24, a partition wall 56
terminates in a closure seat 58. The closure seat includes a
vertically extending seating flange 60 defining the periphery of an
access port 62. The vertical extension of the seating flange 60 is
presented to allow the closure seat 58 to receive a vertically
introduced closure. In spite of the vertical orientation of the
seating flange 60, the closure seat 58 does not terminate in a
plane, as can be seen in FIG. 2. A potting cavity 64 is defined on
one side of the partition wall 56 which, in the final orientation,
opens downwardly. The partition wall 56 with the closure seat 58 in
the bottom body portion 24 is above the hole 50 which is sealed
with closure plate 52 to define a junction box cavity.
Also integral with the bottom body portion 24, a seating hub 66
extends to directly beneath the lens opening 30 to form a mounting
hub with a hole there through for a fastener. A keyway 68 is found
on the inner surface of the bottom body portion 24 as well.
With the housing portions 22, 24, 52 assembled, a sealed lamp
cavity 70 and a junction box cavity 72 are created with the
partition wall 56 bifurcating the housing cavity to form these two
volumes. The cavities 70, 72 are sealed from the outside with a
lens closing the lens opening 30 and from each other through a
closure 74. The access port 62 defined in the partition wall 56 and
bounded by the closure seat 58 extends between two levels in the
housing 20. In doing so, the access port 62 provides an opening for
lateral access from beneath the lens opening 30 toward the
periphery of the housing 20. Thus, the access port 62 faces the
lamp cavity 70 defined within the housing 20.
The access port 62 is closed by the closure 74. The closure 74
includes a peripheral channel 76 receiving the closure seat 58 to
mate with the vertically extending sealing flange 60. A first
portion of the channel is found at a lower level, a second portion
of the channel is found at an upper level and two portions of the
channel extend between the lower and upper levels. Because the
closure seat 58 includes a vertically extending sealing flange 60,
the peripheral channel 76 engages the flange 60 by moving
vertically from the lens opening 30. As the access port 62 is
directly below the lens opening 30, placement of the closure 74 is
facilely completed. Additionally, a key 78 fits into the keyway 68
to insure proper orientation.
The closure 74, inwardly of the peripheral channel 76, includes a
truncated conical wall 80 cut away to create the peripheral profile
discussed. Additionally, the closure 74 includes a plate 82 that
extends across the bottom wall 48. The plate 82 is dished to form a
segment of a sphere with a surface generating radius having a
center of curvature near a point about which the light source is
mounted to pivot to give clearance to the assembly of the light
source. The plate 82 has a hole 84 there through concentrically
positioned and receiving a fastener. The junction box 72, which is
laterally displaced from below the lens opening 30, is fully
accessible through the lens opening 30 with the lens removed and
with vertical removal of the closure 74. A boss 86 with a threaded
insert 88 is located in the closure plate 52 to receive the
fastener and O-ring positioned through the hole 84 in the plate 82.
The seating hub 66 is between the boss 86 and the plate 82 such
that the fastener is able to draw these components together to
firmly seal the peripheral channel 76 on the vertically extending
sealing flange 60 with the help of a gasket 90.
The lamp cavity 70 extends laterally in a volume sufficient to hold
a conventional ballast assembly. This volume provides increased
cooling without requiring further housing depth. A ballast assembly
92 is positioned within the lamp cavity 70 extending laterally from
beneath the lens opening 30 when the light source requires same.
The ballast assembly 92 can be easily extracted from the lens
opening 30 for repair or maintenance. The ballast assembly also has
quick disconnect connectors 94, 96 to facilitate removal as well as
a handle 98 with which to withdraw the ballast assembly 92 from the
lamp cavity 70.
A socket assembly, generally designated 100, is illustrated in
place in FIGS. 2 and 3 and separately in FIGS. 4 and 5. The socket
assembly 100 is illustrated in two embodiments, one with a
reflectorized lamp and the other with a non-reflectorized lamp
which requires the inclusion of a separate reflector. The
difference does not impact the present concepts. The socket
assembly 100 depends from adjacent the lens seat 28. The assembly
includes a mount, generally designated 102, which includes a
mounting ring 104 that sits upon the annular retaining flange 42 in
the cylindrical passageway 40 associated with the lens seat 28.
The mounting ring 104 includes three upstanding mounts. A first
mount 106 receives and threadably engages a screw 108 which extends
radially outwardly. This screw 108 can be extended to engage the
lens seat 28 within the cylindrical passageway 40 to prevent
rotation of the mounting ring 104. Conversely, the screw 108 can be
loosened so that the mounting ring 104 can be rotated about a
vertical axis. The second and third mounts 110, 112 are
diametrically opposed from one another and provide a common axis
for pivotal motion about the mounting ring 104.
The socket assembly 100 further includes a depending mounting strap
114 which is pivotally mounted to the pivot mounts 110, 112 and
extends down to mount a lamp socket 116 aligned with the lens
opening 30. The socket 116 is in electrical communication with the
ballast assembly 92 through the connector 96. The mounting strap
114 is also grounded through the connector 96. In FIG. 5, a
reflector 118 is affixed to the mounting strap 114 where the light
source does not employ a reflectorized lamp.
FIG. 3 illustrates in dashed lines the adjustment possible with
rotation about the mounts 110, 112. By also rotating the mounting
ring 104, a range of universal angular adjustments can be made for
directing the light from the lamp. This adjustment is sufficient to
allow a selection within the useful angular range of the lens
opening as further tilting of the socket assembly 100 is limited by
the truncated conical wall 80 of the closure 74 which prevents the
socket assembly 100 from direct light beyond the lens 120 opening
in light shining on the interior of the lamp rather than through
the lens.
A lens, generally designated 120, includes a sight glass 122 having
an outer surface 124 through which light is to pass. The outer
surface may have a raised textured pattern thereon to avoid
slipping. A mounting flange 126 extends about the periphery of the
sight glass 122 and is displaced axially from the outer surface
124. A cavity 128 inwardly of the mounting flange 126 is adjacent
the sight glass 122. A sealing groove 130 is about the underside of
the mounting flange 126. The mounting flange 126 contains notches
127, as seen in FIG. 11, inwardly of peripheral diameter, which
allows fasteners 129 to be positioned inwardly of the peripheral
diameter. These notches 127 allow for the sight glass 122 to be of
maximum diameter for the passage of light while minimizing the
outer cylindrical body 32 diameter. The lens 120 is positioned in
the lens seat 28 within the outer cylindrical body 32 on the
annular mounting shelf 34. The cylindrical sealing flange 38
extends into the sealing groove 130.
A formed gasket 132 is positioned about the mounting flange 126. A
first portion 134 is cylindrical to surround the sight glass 122.
Below the cylindrical portion 134, a three-sided portion 136
extends across the upper, lower and peripheral sides of the
mounting flange 126. The gasket 132 has keyed inward molded
protrusions 137 that partially fill the notches 127 of the mounting
flange 126. Through these molded protrusions 137 are molded through
holes 131 of such a diameter as to capture the fasteners 129 and
hold them in position. The gasket 132 then continues inwardly to
extend between the cylindrical sealing flange 38 on the lens seat
28 and the sealing groove 130 on the lens 120. This culminates in
an inwardly extending portion 138 which intrudes into lower portion
of the cavity 128. This intrusion allows capture of wafer-shaped
optics which fit within the cavity 128 such as filters and colored
lenses.
A locking ring 140 retains the lens 120 in place. The fasteners 129
threaded into the inserts 46 in the annular mounting shelf 34 hold
the locking ring 140 in place. The locking ring 140 engages the
upper edge 36 of the outer cylindrical body 32 to restrict its
travel regardless of the torque placed on the retaining fasteners.
This prevents the mounting flange 126 from being tightened to
damage the gasket 132 placed in interference fit between the
cylindrical sealing flange 38 and the sealing groove 130, yet the
axial distance between the edge 36 and the sealing flange 38 can
allow the formed gasket 132 to be brought into compression for
sealing between the cylindrical sealing flange 38 and the sealing
groove 130. The cylindrical portion 134 of the formed gasket 132
may be sized to fill the gap between the sight glass 122 and the
locking ring 140. In addition to the locking ring 140, a rock guard
142 (as seen in FIG. 1) may be employed over the lens 120 and
fastened in association with the locking ring 140. Reference is
made to U.S. Design application Ser. No. 29/296,394, filed Oct. 19,
2007.
The locking ring 140 has axial countersunk holes 143 there through
to align the locking ring 140 with the holes 131. The fasteners 129
each include a smooth shank 141 and an enlarged threaded end 147 to
capture the molded protrusions 137 through avoiding facile
withdrawal of the fasteners 129 through the axial through holes
131. This can keep the lens assembly, including the lens 120, the
gasket 132, the locking ring 140 and the fasteners 129 together for
easy reassembly with the housing 20.
Electrical wires 144 extend through a grommet 146 located in the
partition wall 56. The wiring 144 extends from the grommet into the
lamp cavity 70 to the connector 94 for coupling with the ballast
assembly 92 or the socket assembly 100. The wiring 144 extends from
the grommet into the junction box cavity 72 and into the potting
cavity 64. In the potting cavity 64, the wiring 144 is spliced to
electrical supply leads 145 in such a manner as to form a
waterproof wicking barrier. This waterproof wicking barrier is
created by individually soldering the ends of the both the
electrical supply leads 145 and the ends of the wires 144, then
crimping them together such that potting material poured into
potting cavity 64 forms an intimate bond on the solidified wires
surfaces, preventing water from passing through the potting
material. The electrical leads 145 emerging from the potting
material into the junction box cavity 72 are employed for making
the appropriate connections to electrical supply wiring.
The closure plate 52 has molded threaded holes 148 for receiving
electrical supply wiring for connection to the electrical leads
145. The holes 148 are configured for standardized conduit. As the
electrical supply wiring is solid wire rather than stranded and is
typically pulled in through conduit after the fixture installation
using a fish tape or other apparatus, the holes are arranged and
positioned such that there need be very little bending of the wire
as it is pulled into the junction box by apparatus introduced to
the supply conduit though the access port 62 and the junction box
72. The access port 62 is designed in contemplation of the
difficulty with handling solid wire for installation or renewal. It
is anticipated that moisture will ultimately be introduced through
the conduit or supply wiring into the junction box 72. The
partition wall 56, grommet 146 and closure 74 define a moisture
proof barrier to keep the lamp cavity 70 dry.
In operation, the housing 20 is presented at the placement site.
The electrical leads 145 emerging from the potting material are
connected to the electrical supply wiring from power supplied to
the site. This electrical supply wiring is positioned through one
or more threaded holes 148 located about the sidewall of the bottom
body portion 24 or from the bottom threaded hubs of the closure
plate 52. Connections are made with appropriate splicing nuts and
are made through the access port 62. Once complete, the spliced
wiring is facile positioned entirely into the junction box cavity
72, and this junction box cavity 72 is sealed from the lamp cavity
70 with closure 74 using a single fastener and O-ring. The junction
box may potentially be subjected to moisture without substantial
harm.
In instances where socket assemblies 100 require the use of ballast
assemblies 92 to properly operate the lamp, the ballast assembly 92
is positioned laterally of the lens opening 30 within the housing
20, and the wiring 144 is connected to ballast connector 94. The
socket assembly 100 is lowered into the lens opening 30 and
connector 96 is connected to ballast assembly 92. The socket
assembly 100 is then fully lowered in place, supported by the
mounting ring 104 on the annular retaining flange 42. Where lamp
types that operate directly on incoming electrical power without
the need for ballasts, the connector 94 couples directly to lamp
connectors 96. Differences in the quantity and shapes of connectors
92, 94, and 96 determine the connection coupling pairings. The
direction of light may then be achieved by manipulating the mount
102 and locking the orientation in place. Finally, the lens 120 is
positioned within the gasket 132 thereabout in the lens seat 28.
The locking ring 140 is then affixed.
For maintenance, the lens 120 is removed followed by the socket
assembly 100. Relamping can then occur. If further operations are
required to repair or replace the ballast assembly 92, this can be
withdrawn through the lens opening 30. Finally, if rewiring is
necessary, the closure 74 may be withdrawn from the housing 20. The
fastener at the center of the closure plate 82 is withdrawn and the
wire handle 150 may be grasped to pull the closure 74 from the
housing 20. With the closure 74 removed, the re-wiring of the
fixture can be addressed through the lens opening 30 without
requiring removal of the housing 20 from its in-grade position. The
gasket 90 may be replaced and the process reversed for
assembly.
Turning next to FIGS. 8 through 10, a fixture employing an LED
array is illustrated. Common elements between embodiments employ
identical reference numbering for brevity. The mount 102 supports
mounting straps 114 much as in the prior embodiment. These mounting
straps 114 mount an LED circuit board array 152. Such circuit board
arrays 152 are commonly mounted on metal heat transfer
materials.
The array 152 is securely bolted for maximum thermal conductivity
to a heat sink 154. The heat sink 154 is of high heat transfer
metal. The heat sink 154 includes a plate 156 which is coextensive
with the LED circuit board array 152. Further, the heat sink 154
includes a thermal block 158 depending from the plate 156. A molded
radiator 160 is also of thermally conductive material and includes
a central block 162 in thermal conductivity with the thermal block
158. Integral fins 164 extend radially outwardly from the central
block 162. Fasteners may retain this assembly together. Viewing the
assembly in FIG. 8, the radiator 160 is shown to be located in the
main body of the lamp cavity 70. Rather than heat traveling
upwardly from convection, heat moves rapidly by conduction to the
radiator 160 in a downwardly direction for radiation into the
larger cavity of the lamp housing 20. This larger cavity is better
able to dissipate heat from the LED array 152 than the area above
the array 152 and below the lens 120. An LED power control 166
takes the place of the ballast assembly 92 of the prior embodiment.
The power control 166 is positioned laterally from beneath the lens
opening 30 in the lamp cavity 70. Assembly and maintenance
procedures are near identical between embodiments.
Thus, a sealed in-grade fixture of improved performance and
adaptability is disclosed. While embodiments and applications of
this invention have been shown and described, it would be apparent
to those skilled in the art that many more modifications are
possible without departing from the inventive concepts herein. The
invention, therefore, is not to be restricted except in the spirit
of the appended claims.
* * * * *